DIABETES MELLITUS STUGY GUIDE WITH
QUESTIONS AND DETAILED ANSWERS THE LATEST
UPDATED EXAM BANK INCLUDING EXPERT
VERIFIED SOLUTIONS FOR A SURE PASS
Insulin by duration of action
Patients often require a mixture of preparations (e.g. both short and long acting) to
ensure stable glycaemic control throughout the day.
What is diabetes mellitus?
Metabolic disorder characterised by persistent hyperglycaemia, with disturbances
of carbohydrate, fat and protein metabolism resulting from defects in insulin
secretion, insulin action, or both.
Diabetes mellitus is a net deficiency of...
insulin leading to imbalance in glucose production and utilization.
diabetes can be diagnosed by:
Characteristics of Diabetes Mellitus AND 1 of:
-Random Blood Glucose >11.0mmol/L
-Fasting blood Glucose >7.0 mmol/L
-HbA1c >48mmol/mol
Random blood glucose diabetes
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Random Blood Glucose >11.0mmol/L
Fasting blood glucose diabetes
Fasting blood Glucose >7.0 mmol/L
Physiology recap
When our blood sugar rises, the pancreas secretes insulin which increases glucose
uptake by cells or converts it into glycogen (glycogenesis) which is stored in the
liver. This will stabilise the glucose levels in the blood.
When our blood glucose drops, the pancreas will secrete glucagon, which causes
glycogen to be broken back down into glucose (glycogenolysis) and the liver will
synthesis glucose (gluconeogenesis)
T1DM = absolute insulin deficiency
T2DM = insulin resistance
HbA1c in diabetes
>48mmol/mol
What is type 1 diabetes?
Absolute insulin deficiency causing persistent hyperglycaemia.
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Pathophysiology of type 1 diabetes?
Usually due to autoimmune destruction of the insulin-producing beta cells in the
pancreas.
Risk factors of type 1 diabetes
Genetic - a heritable polygenic disease.
Environmental - may trigger an autoimmune response:
-Diet.
-Vitamin D exposure.
-Obesity
-.Exposure in early life to viruses associated with islet inflammation, e.g.
enteroviruses.
-Decreased gut-microbiome diversity.
Prognosis of type 1 diabetes
Without insulin replacement, people with T1DM would die within days or weeks.
With insulin replacement, people with T1DM can participate in usual activities of
daily life, however are at risk of complications.
Keeping circulating blood glucose levels as near normal range as possible reduces
the risk of complications by reducing tissue damage.
Presentation of type 1 diabetes
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Suspect type 1 diabetes in a child or young person presenting with hyperglycaemia
(random plasma glucose more than 11 mmol/L) and the characteristic features of:
Polyuria.
Polydipsia.
Weight loss.
Excessive tiredness.
Diagnose type 1 diabetes on clinical grounds in adults presenting with
hyperglycaemia (random plasma glucose more than 11 mmol/L), bearing in mind
that adults with type 1 diabetes typically (but do not always) have one or more of
the following:
Ketosis.
Rapid weight loss.
Age of onset younger than 50 years.
Body mass index (BMI) below 25 kg/m.
Personal and/or family history of autoimmune disease.
What is polydipsia and why does it occur in hyperglycaemia?
excessive thirst
Polydipsia, thirst, occurs due to water lost through increased urination.
Why is there increased volume and frequency of urination in hyperglycaemia?
Urinary volume (and consequently frequency) is increased through the process of
osmotic diuresis.